Twenty-first, inclusive, and Cook's light artillery battery, which is refitting. Sixteenth Regiment, Colonel Wyman, was under orders to leave yesterday, but is delayed by operation of General Orders, Numbers 50, and by severe rain-storm during last few days. Strength of others yesterday was: Seventeenth, 800 men; Eighteenth, 650 men; Nineteenth, 550 men; Twentieth, 500 men; Twenty-first, 750 men. Officers of Seventeenth and Twenty-first are not formally appointed, because of desire for first-class field officers, which are exceedingly difficult to obtain here. We have applied in vain to you for a furlough for Captain Amory, Seventh Infantry, now here recruiting, and for other Army officers, to take colonelcy in case of emergency. These five regiments can leave before first week of September. They have been under drill several weeks, with promise from Washington to accept all we raise under reasonable condition concerning inspection, & c., and with proper officers several more full regiments can be cheerfully raised during autumn - three certainly before end of September, in effective condition; but action of War Department in delaying payment to our militia regiments and withholding allowances from them has discouraged re-enlistments, on which we much relied for efficiency of new regiments. Sixth and Eighth militia regiments not yet paid off. Their men, therefore, have as yet no opportunity to re-enlist, and they are dissatisfied.

ALBERT G. BROWNE, JR.,

Military Secretary.

WAR DEPARTMENT,

Washington, August 15, 1861.

Governor ANDREW,

Boston:

Message received. Please urge your people to fill up regiments immediately. Would like to have at least five regiments from you next week, with as many batteries of artillery as you can equip and have ready for service. I will start paymasters to-morrow, and you can give assurances that all will be promptly paid. Our three-months' forces all going out of service at one time has caused some delay in Paymaster-General's Department.

SIMON CAMERON,

Secretary of War.

WAR DEPARTMENT,

Washington City, August 15, 1861 - 9.41 a. m.

A. S. PADDOCK,

Governor of Nebraska, Omaha:

Will accept two more companies cavalry.

SIMON CAMERON.

CONCORD, N. H., August 15, 1861.

Honorable S. CAMERON:

We can have one regiment ready to go from our State by the 1st day of September; another the 1st of October, and possibly sooner.

NATHL. S. BERRY,

Governor.